Byte Converter
Bytes through terabytes, in binary multiples of 1024.
Type into any field and the rest follow.
The 1000 versus 1024 problem
There are two competing definitions of a kilobyte and both are in daily use. Software mostly counts in binary, where each step up is a factor of 1024, because that is how memory is addressed. Storage manufacturers count in decimal, where a kilobyte is 1000 bytes, because it makes the number on the box larger.
The gap compounds with every step: 2.4% at kilobytes, 4.9% at megabytes, 7.4% at gigabytes, and about 10% by terabytes. That is the entire explanation for why a drive sold as 1 TB shows up as roughly 931 GB. No space is lost — the two systems are just counting the same bytes against different bases.
The IEC units — KiB, MiB, GiB — were introduced to end the ambiguity, and 1 KiB is exactly 1024 bytes by definition. Adoption is partial: Linux and macOS tooling increasingly uses them, while Windows still writes KB and means KiB. This converter uses binary multiples throughout, so it matches what your operating system tells you.
Frequently asked questions
Is a kilobyte 1000 or 1024 bytes?
Both definitions are in use. This converter uses 1024, the binary multiple that Windows and most software report. Storage manufacturers use 1000, which is why a drive sold as 1 TB shows as roughly 931 GB once formatted — the same bytes, counted against a different base.
What are KiB, MiB, and GiB?
They are the unambiguous binary units: 1 KiB is exactly 1024 bytes. They exist precisely because KB is ambiguous. macOS and Linux tools increasingly report these, while Windows still says KB while meaning KiB.
Why does my 1 TB drive show as 931 GB?
The manufacturer counted 1,000,000,000,000 bytes; your operating system divides by 1024 three times, giving about 931. Nothing is missing — the two are just counting in different bases.
How many bytes is a megabyte here?
1,048,576 — that is 1024 × 1024. A gigabyte is 1,073,741,824, and a terabyte is 1,099,511,627,776.
Why do small values show so many decimal places?
Because binary fractions rarely land on round decimals. One megabyte is 0.0009765625 GB exactly — that is 1/1024, not a rounding artefact.